The Impact of Expandable Cryoballoon on Autonomic Control of the Heart

This study examines how using an expandable cryoballoon catheter for pulmonary vein isolation (PVI) — a procedure to treat atrial fibrillation (irregular heartbeat) — affects the heart's autonomic nervous system, which controls the heart's natural pacemaking and rhythm. **You may be eligible if...** - You have paroxysmal atrial fibrillation (episodes that come and go on their own) - You are having your first PVI procedure - You are in normal sinus rhythm at the time of admission - You meet clinical criteria for PVI based on your cardiologist's assessment **You may NOT be eligible if...** - Your left atrium is either too small (less than 38 mm) or too enlarged (greater than 50 mm) - Your heart's pumping function is significantly reduced (ejection fraction below 40%) - You have disease of the heart's natural pacemaker (sinus node disease) - You have advanced heart block or a very long PR interval - You have had a prior cardioneuroablation procedure - You are pregnant, on anticoagulation contraindications, or have other clinical reasons preventing PVI Talk to your doctor to see if this trial is right for you.